Design for portable electronic musical key board



FIG. 1 is a top perspective view of a portable electronic musical keyboard showing my new design;

FIG. 2 is a right side perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a rear elevational view thereof;

FIG. 7 is a left side elevational view thereof; and

FIG. 8 is a right side elevational view thereof.

The shoulder belt has been omitted in FIGS. 2-8 inclusive for ease of illustration only. 

The ornamental design for portable electronic musical key board, as shown and described. 